Some sets you buy because the model makes for a lovely display piece, even though it doesn't have much for play features or interactivity. #10143
Death Star II is an example. Set these types of sets aside for now....
Some sets you buy because the minifigures are awesome, though the model is lacking; many early superhero sets are characterized this way. Set these aside too.....
And then there are some sets that have the magic combination of eye-catching design, clever minifigures, and wildly fun play features. These are the sets that highlight everything Lego can be when it is hitting on all cylinders. These are the sets that are so good, you might buy them even though you don't necessarily collect their themes. These are the sets that are so much fun, you just can't keep your hands off them. Remembering that Lego is first and foremost a TOY and should be played with, I call these the "All-Time Classics", and here's my list so far:
Black Seas Barracuda -- THE classic pirate ship, loaded with figures, features, and even animals. Even if you're not a Pirates fan, you have to admit she cuts a pretty profile.
Haunted House -- When October rolls around, everyone who doesn't have this set (including me) wishes they did. A gorgeous, gothic masterpiece.
Benny's Spaceship, Spaceship, SPACESHIP! -- The actual physical embodiment of "Swoosh!", with great minifigures to boot.
Ewok Village -- A boatload of furballs and core characters packed in a set that's filled with play features and has an obvious vintage Kenner influence. The design was great in 1983, and got even better in 2013.
Medieval Market Village along with #7189
Mill Village Raid -- Proving that there was more to the Castle theme than just castles. Now the Kingdoms have actual peasants to fight over!#8635
Mobile Command Center -- It's a vehicle! It's a base! Wait, it's actually a whole bunch of vehicles! It even lights up!
Temple of Airjitzu -- Even if you're not into the Ninjago storyline (like me), you have to admit this is a beautiful set. I've seen plenty of folks on the boards saying this will be their first and only Ninjago purchase, and I'll likely soon be joining them.
Town Plan -- Just look at that Art Deco movie theater! This is Anytown USA writ small, and there's so much to do, you'll never be bored.
As you think over the entire history of minifigure-based Lego sets, what ones do YOU consider to be All-Time Classics?